Collapsible wheels and methods of making collapsible wheels

ABSTRACT

Embodiments of collapsible wheels and methods of making collapsible wheels are generally described herein. Other embodiments may be described and claimed.

RELATED APPLICATION

This application is a continuation-in-part of U.S. patent applicationSer. No. 14/337,640, filed on Jul. 22, 2014, which is a continuation ofU.S. patent application Ser. No. 14/063,601, now U.S. Pat. No.8,833,864, filed on Oct. 25, 2013, which claims the benefit of U.S.Provisional Patent Application Ser. No. 61/719,634, filed Oct. 29, 2012,the disclosures of all of which are herein incorporated by reference.

FIELD

The present application generally relates to wheels, and more generallyto collapsible wheels and methods of making collapsible wheels.

BACKGROUND

Some sporting equipment may require a wheeled vehicle fortransportation. For example, kayaks may be transported to a river orlake on a wheeled kayak cart. Prior to launching the kayak on water, thekayak cart is removed from the kayak and may be stored on the kayak. Thekayak cart may have a frame that is collapsible to reduce the size ofthe cart when not in use. In another example, an individual playing golfcan carry his golf bag on his shoulder, with a golf pull cart or anelectric golf cart. Golf pull carts typically have a frame to which twowheels for moving the cart are attached. The frame may also include ahandle that is held by an individual for balancing, pulling or pushingthe cart, and a platform or base for mounting the individual's golf bag.The frame may be collapsible to reduce the size of the pull cart whennot in use for storage and/or transportation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a wheel according to one embodimentshown in an expanded position.

FIG. 2 is a perspective view of the wheel of FIG. 1 shown in a collapsedposition.

FIG. 3 is a perspective view of the wheel of FIG. 1 shown without a tireaccording to one embodiment.

FIG. 4 is a perspective view of the wheel of FIG. 3 shown in thecollapsed position.

FIG. 5 is a perspective view of two wheel sections of the wheel of FIG.1.

FIG. 6 is a partial front perspective view of the wheel of FIG. 1 shownin the expanded position.

FIG. 7 shows a tire for use with a wheel according to one embodiment.

FIGS. 8-9 show sections of the tire of FIG. 7.

FIGS. 10-11 show mounting of the tire of FIG. 7 on the wheel of FIG. 3according to one embodiment.

FIG. 12 shows a wheel section of the wheel of FIG. 1.

FIG. 13 shows an axle for the wheel of FIG. 1.

FIG. 14 shows the axle of FIG. 13 mounted in the wheel of FIG. 1.

FIGS. 15-18 show the wheel of FIG. 1 with an expansion and collapsingmechanism according to one embodiment.

FIGS. 19 and 20 show a wheel according to another embodiment in anexpanded position and a collapsed position, respectively.

FIGS. 21 and 22 show a wheel according to another embodiment in acollapsed position.

FIGS. 23-25 show the wheel of FIGS. 21 and 22 in an expanded position.

FIG. 26 shows a side view of a wheel according to one embodiment.

FIG. 27 shows a side view of a wheel according to one embodiment.

FIGS. 28 and 29 show side views of a wheel according to one embodimentin the expanded position and the collapsed position, respectively.

FIGS. 30 and 31 show side views of a wheel according to one embodiment.

FIGS. 32 and 33 show perspective views of a wheel according to oneembodiment.

FIG. 34 shows a partial perspective view of the wheel section of a wheelaccording to one embodiment having a tire section.

FIGS. 35, 36 and 38 show a wheel according to one embodiment in anexpanded position.

FIGS. 37, 39 and 40 show the wheel of FIG. 35 in a collapsed position.

FIG. 41 shows perspective cross-sectional views of spokes of the wheelof FIG. 35.

FIG. 42 shows a flow chart of a method to manufacture a wheel accordingto one embodiment.

FIGS. 43 and 44 show a cart for carrying a golf club bag in deployed andstowed positions, respectively, having wheels according to oneembodiment.

FIG. 45 shows a perspective view of another embodiment of a wheel in anexpanded position and having a track assembly.

FIG. 46 shows a perspective view of the wheel of FIG. 45 in a collapsedposition.

FIG. 47 shows a side view of the wheels of FIGS. 45 and 46, comparingthe collapsed position to the expanded position.

FIG. 48 shows a side view of a wheel section of the wheel of FIG. 45.

FIG. 49 shows a perspective view of a track segment of the wheel of FIG.45, illustrating an outer surface.

FIG. 50 shows a perspective view of the track segment of FIG. 49,illustrating an inner surface.

FIG. 51 shows an end view of the track segment of FIG. 49, taken alongline 51-51 of FIG. 49.

FIG. 52 shows a side view of the track segment of FIG. 49, taken alongline 52-52 of FIG. 51.

FIG. 53 shows a perspective view of a portion of the track assembly ofFIG. 45 illustrating the outer surface.

FIG. 54 shows a perspective view of a portion of the track assembly ofFIG. 53, illustrating the inner surface.

FIG. 55 shows a perspective view of a wheel section of the wheel of FIG.45 configured to be secured to the portion of the track assembly of FIG.53.

FIG. 56 shows a perspective view of the wheel of FIG. 45, illustrating aspacer that is positioned between adjacent wheel sections.

FIG. 57 shows a perspective view of another embodiment of a wheel in anexpanded position and having a track assembly.

FIG. 58 shows a perspective view of a portion of the track assembly ofthe wheel of FIG. 57, taken along line 58-58 of FIG. 57.

FIG. 59 shows a perspective view of the wheel of FIG. 57 with a portionof the track assembly removed to further illustrate the wheel sectionsin the expanded position, and a portion of the track assembly secured toa wheel section.

FIG. 60 shows a perspective view of the wheel of FIG. 57, with a portionof the hub assembly removed to illustrate only a single wheel section.

FIG. 61 shows a perspective view of the wheel of FIG. 60, illustratingan opposing side to that of FIG. 60.

FIG. 62 shows a perspective view of an alternative track segment for usewith the track assembly of the wheel of FIG. 57, illustrating an outersurface.

FIG. 63 shows a perspective view of the track segment of FIG. 62,illustrating an inner surface.

DETAILED DESCRIPTION

Referring to FIGS. 1 and 2, a wheel 100 according to one example of theapparatus, methods, and articles of manufacture described herein isshown. The wheel 100 includes a hub assembly 102 and a tire 104, atleast a portion of which is mounted around the hub assembly 102 forcontact with the ground. The wheel 100 also includes an axle 106 overwhich the hub assembly 102 is rotatably mounted. A wheel 100 or aplurality of wheels 100 may be used on a cart or a vehicle fortransporting any object.

FIG. 1 shows the wheel 100 in an expanded position. To reduce the sizeof the wheel 100 for transportation and/or storage, an individual maycollapse the wheel 100 to a collapsed position shown in FIG. 2. Forexample, a trunk of an automobile may not have sufficient space toaccommodate a pull cart for golf clubs when the wheels 100 of the pullcart are in the expanded position. By placing the wheels 100 in thecollapsed position, the pull cart and the wheels 100 may fit inside thetrunk of the automobile for transportation. Accordingly, collapsing thewheels from an expanded position to a collapsed position allows thewheels and or any object to which the wheels are attached to occupy lessspace. Furthermore, as discussed in detail below, each wheel 100 may beremovable from a pull cart to further reduce the space that may beoccupied by the pull cart and the wheels 100.

Referring also to FIGS. 3-6, the hub assembly 102 is shown in theexpanded and collapsed positions, respectively. The hub assembly 102includes a plurality stacked wheel sections 110. Each wheel section 110includes a hub section 112 with a central bore 114. The wheel sections110 may be concentrically stacked so that the central bores 114 areaxially aligned to form an elongated bore for receiving the axle 106.Each wheel section 110 may include at least one spoke 116 and a rim 118.In the example of FIGS. 1-5, each wheel section 110 has a first pair ofspokes 116 that radially projects from the hub section 112 to connect toa first rim 118, and a second pair of spokes 116 that radially projectsfrom the hub section 112 opposite to the first pair of spokes 116 toconnect to a second rim 118. Each rim 118 receives and supports asection of the tire 104. Each wheel section 110 may include any numberof spokes 116 that extend from the hub section 112 to one or more rims118. For example, each rim 118 may be connected to only one spoke 116 ora plurality of spokes 116. The spokes 116 may be in any shape. Forexample, each spoke 116 may be straight, bent in one or more locationsalong the length of the spoke, and/or have a curvature. In the examplesof FIGS. 1-5, the spokes 116 may be curved so as to function as springswhen the wheel 100 is used. Accordingly, when forces are exerted on therim 118 during the operation of the wheel 100, the curved shape of eachspoke 116 facilitates elastic bending of the spoke 116 such that thespoke 116 provides a shock absorbing function.

Each wheel section 110 may be freely rotatable about the axle 106 toallow expansion of the wheel sections 110 from a collapsed positionshown in FIG. 4 to an expanded position shown in FIG. 3. The number ofwheel sections 110, the thickness of each wheel section 110, and/or theradial span of each wheel section 110 may be determined so that in theexpanded position of the wheel 100, a full circular wheel, i.e., about360°, is defined by the wheel 100 and the rims 118 provide sufficientsupport for the tire 104 for proper operation of the wheel 100.Providing sufficient support for the tire 104 at any instant during theoperation of the wheel 100 may be defined by the number of contactpoints between the wheel 100 and the ground. Each rim 118 may be definedas having one contact point, which although referred to herein as acontact point, may represent an area of the rim 118 that contacts theground. Increasing the number of contact points between the wheel 100and the ground may increase the stability of the wheel 100, henceincrease the stability of the vehicle, i.e., pull cart, to which thewheel 100 is attached.

The radial span of each wheel section 110 may determine the radialposition of each wheel section 110 relative to an adjacent wheel section110 in the expanded position of the wheel 100 and the number of wheelsections 110 that may be needed. Radial span 119 as shown in FIG. 5 andas used herein may generally define a length of the rim 118 thatcontacts the ground during the operation of the wheel 100. For example,if each rim 118 of a pair of rims 118 of a wheel section 110 define aradial span of about 90°, only two wheel sections 110 may be required sothat the rims 118 define a full circle or about 360° without generallyany overlap or gap between two adjacent rims 118; or each rim 118 maygenerally define a 90° radial span on a full circle that defines thewheel 100. In other words, each wheel section 110 may generally define a180° radial span on a full circle that defines the wheel. In anotherexample, if each rim 118 of a pair of rims 118 of a wheel section 110has a radial span 119 of about 45°, four wheel sections 110 may berequired, i.e., eight rims 118, so that the rims 118 define a fullcircle or about 360° without generally any overlap or gap between twoadjacent rims 118. Accordingly, a general configuration of the wheel 100may be defined by the following example equation:

$\begin{matrix}{{\frac{360{^\circ}}{NW}C} = R} & (1)\end{matrix}$

Where W represents the number of wheel sections, N represents the numberof opposing rims 118 on each wheel (e.g., N is 2 in the example of FIGS.2-5), C represents the number of ground contact points, and R representsthe radial spacing of each wheel section relative to an adjacent wheelsection (in degrees).

As described above, increasing the number of contact points between thewheel 100 and the ground may increase the stability of the wheel 100.Each rim 118 may contact the ground at one contact point. By providingmultiple contact points, i.e., multiple rims 118, which contact theground at any instant, the stability of the wheel 100 may increase. Inother words, increasing the number of contact points with the ground atany instant during the operation of the wheel 100 increases the width ofthe wheel 100, thereby increasing the number of wheel sections 110 thatmay be used to form the wheel 100.

Referring to FIG. 5, an example of the wheel 100 is shown where eachwheel section has a rim 118 that has a radial span 119 of about 45°.Accordingly, adjacent wheel sections 110 may be generally radiallyspaced apart by about 45° in the expanded position of the wheel 100 asshown in FIG. 5. In the example of FIG. 5, four wheel sections 110,i.e., eight rims 118, would be required to define a full circle or about360°. Thus, if the wheel 100 is constructed with four wheel sections110, only one rim 118, i.e., one contact point, contacts the ground atany instant. To increase the stability of the wheel 100, sixteen wheelsections 110 may be provided as shown in the example of FIG. 4 so thatat any instant during the operation of the wheel 100, four contactpoints on the wheel 100 contact the ground, i.e., four rims 118 definethe width of the wheel 100. Any number of wheel sections 110 may beprovided for increasing or reducing contact points. For example, twentywheel sections 110 would provide five contact points with the ground atany instant for the wheel 100. In another example, twelve wheel sections110 would provide three contact points with the ground. According to theabove, when each rim 118 spans about 45°, at least eight rims 118 may berequired so that at any instant during the operation of the wheel 100one contact point contacts the ground. To increase the number of contactpoints along the width of the wheel when each rim 118 has a radial span119 of about 45°, multiples of four wheel sections 110 may be provided.In the example of FIG. 4, sixteen wheel sections 110 for the wheel 100provide four contact points at any instance during the operation of thewheel as shown in FIG. 6.

Increasing the number of wheel sections 110 may increase the stabilityof the wheel 100 and/or the amount of weight that the wheel 100 maysupport. However, increasing the number of wheel sections 110 may alsoincrease the size and/or the weight of the wheel 100 in the collapsedposition. Accordingly, the size of each wheel section 110, and otherproperties of each wheel section 110 as described herein may bedetermined depending on the size and load of the cart to which one ormore wheels 100 may be attached.

FIG. 6 illustrates an expanded position of two wheel sections 110. Therim 118 of each wheel section 110 includes a radial projection 120.Referring to FIGS. 7-11, the tire 104 may include an inner surface 130and an outer surface 132. The outer surface 132 may be smooth or havetreads. The inner surface 130 may have any configuration to providemounting of the tire 104 on the rims 118. In the examples of FIGS. 8 and9, the inner surface 130 includes a plurality of generally parallel ribs134 that define a plurality of generally parallel grooves 136 betweenthe ribs 134. The ribs 134 and the grooves 136 may radially span aportion of the inner surface 130. In the examples of FIGS. 8 and 9, theribs 134 and the grooves 136 span the entire 360° of the inner surface130 of the tire 104.

Referring to FIGS. 10 and 11, the distance between adjacent grooves 136generally corresponds to the distance between the projections 120 ofadjacent wheel sections 110. Additionally, the cross-sectional shape ofeach groove 136 may generally correspond to the cross-sectional shape ofthe projections 120. Accordingly, when the tire 104 is mounted on thewheel sections 110, the projections 120 may engage the grooves 136 andgenerally fit within the grooves 136. The projections 120 and thegrooves 136 may have any cross-sectional shape. In the example of FIG.11, the projections 120 are shown to have a generally triangularcross-sectional shape and the grooves 136 are also shown to have agenerally corresponding triangular cross-sectional shape. Furthermore,the size of the grooves 136 may generally correspond to the size of theprojections 120. For a tire 104 that is constructed from an elasticmaterial such as rubber, the grooves 136 may be alternatively formed tobe smaller than the projections 120 so that the grooves 136 elasticallyexpand when receiving the projections 120 to provide a generallyformfitting engagement with the projections 120. The tire may beattached to one or more of the rims 118 such that the tire is maintainedin a mounted configuration on the wheel 100 in both the collapsed andexpanded positions of the wheel 100.

As described above, each wheel section 110 may be positioned relative toan adjacent wheel section 110 at a certain angle during the operation ofthe wheel 100 to provide a sufficient number of contact points andgenerally evenly distributed contact point locations for the wheel 100.For example, the wheel sections 110 of FIG. 5 are positioned at about45° relative to each other in the expanded position to provide fourevenly distributed contact points at any instant during the operation ofthe wheel 100. The angle between the wheel sections 110 in the expandedposition that provides a sufficient number of contact points andgenerally evenly distributes the contact point locations on the wheelmay be referred to herein as the expansion angle. The expansion angle isshown in equation (1) as the variable R. Thus, the expansion angle forthe example of FIG. 5 is about 45°.

As described in detail above and with respect to equation (1), theexpansion angle may be different depending on the configuration and/orproperties of the wheel sections 110. To limit the expansion of thewheel sections 110 relative to each other and/or to provide positioningof the wheel sections 110 relative to each other at the expansion angle,the wheel 100 may include an expansion angle limiting mechanism by whichrotation of each wheel section 110 relative to an adjacent wheel section110 is limited to the expansion angle. According to one example shown inFIG. 12, the angle limiting mechanism includes a radial slot 140 on thehub section 112 of each wheel section 110 and a pin 144 that may belocated on the hub section 112 opposite to the slot 142 relative to thecentral bore 114. The arc length of each radial slot 140 may begenerally no greater than the expansion angle. In the example of FIG.12, the arc length of the radial slot 140 is about 45°, which is thesame as the expansion angle. When the wheel sections 110 are assembledas described in detail below, i.e., stacked on top of each other, thepin 144 of each wheel section 110 is placed inside the slot 140 of anadjacent wheel section 110. Accordingly, when adjacent wheel sectionsare rotated relative to each other, the pin 144 moves in the slot 140.However, the radial movement of the pin 144, which defines the radialmovement of the wheel section 110 having the pin 144, is bound by thearc length of the slot 140.

Each slot 140 includes a first end 150 and a second end 152. In thecollapsed position of the wheel 100, the pin 144 of each wheel section110 is located near the first end 150 of the slot 140 of an adjacentwheel section 110. As the wheel 100 is expanded, the pin 144 moves inthe slot 140 from the first end 150 until the pin 144 contacts thesecond end 152 of the slot 140. Thus, the slot 140 limits rotation ofthe two adjacent wheel sections 110 relative to each other to theexpansion angle or the radial arc length of the slot 140. The positionof each slot 140 and pin 144 may be determined to allow expanding andcollapsing of the wheel 100 as disclosed. In the example of FIG. 12, thefirst end 150 of the slots 140 is generally located along a centerlongitudinal axis 154 of the hub section 112. Accordingly, the secondend 152 of the slot 140 is located about 45° from the first end 150. Thepin 144 is also located on the center longitudinal axis 154, but islocated opposite to the first end 150 of the slot 140 relative to thecentral bore 114. As described in detail below, the arrangement of thepin 144 and the slot 140 as shown in FIG. 12 provides for each wheelsection 110 to be rotated relative to an adjacent wheel section by theexpansion angle.

After the wheel 100 is expanded, which is defined by each wheel section110 having the expansion angle relative to an adjacent wheel section110, the wheel 100 may be maintained in the expanded position by anytype of latching, locking and/or similar mechanisms that prevent thewheel sections 110 from rotating relative to each other. For example,each wheel section 110 may include an aperture (not shown) positioned onthe hub section 112 such that when the wheel sections 110 are in theexpanded position of the wheel 100, all of the apertures of the wheelsections 110 are generally aligned to receive a rod (not shown).Therefore, the rod prevents the wheel sections 110 from rotatingrelative to each other. In another example, a U-shaped bracket (notshown) which has a width that is generally similar to the collectivewidth of the hub sections 112 may be placed over the hub sections 112 toprevent the hub sections 112 from rotating relative to each other.

Referring to FIGS. 13 and 14, the wheel sections 110 may be rotationallymounted on an axle 106. The axle 106 may be defined by a cylindricalshaft 160 having a first end 162 and a second end 164. In the example ofFIGS. 13 and 14, the axle 106 may further include a mounting bracket 166having a first bracket section 168 and the second bracket section 170.The mounting bracket 166 may facilitate mounting or attachment of thewheel 100 to a cart, such as a golf pull cart. The wheel sections 110may be mounted on the shaft 160 by inserting the shaft 160 from thefirst end 162 in the central bore 114 of each wheel section 110. Theaxle 106 may include a mechanism by which the first wheel section 110that is mounted on the shaft 160 is held stationary to allow expansionof the wheel 100 from a collapsed position. In one example as shown inFIG. 13, the first bracket section 160 includes a pinhole 170 forreceiving the pin 144 of the first mounted wheel section 110. Engagementof the pin 144 in the pinhole 170 of the first mounted wheel section 110maintains the first mounted wheel section 110 fixed to the first bracketsection 160 to allow expansion of the wheel 100 from a collapsedposition to an expanded position. After the wheel 100 is expanded, thepin 144 may be removed from the pinhole 170 to allow rotation of thewheel 100 about the shaft 160.

The axle 106 may further include a wheel holding mechanism by which thewheel 100 is maintained on the shaft 160 during the operation of thewheel 100. The wheel holding mechanism may include any configuration toprevent the wheel 100 from sliding off the shaft 106 or being removedfrom the shaft 106 during the operation of the wheel 100. For example,the first end 162 of the shaft 160 may be threaded to receive acorrespondingly threaded nut (an example is shown in FIG. 22). Thethreaded nut increases the diameter of the shaft 160 at the first end162 to a diameter that is greater than the central bores 114 of the hubsections 112. Accordingly, the wheel sections 110 are stopped by the nutwhen reaching the first end 162 of the shaft 160.

In the example of FIG. 13, the shaft 160 includes an annular recess 172at or near the first end 162 of the shaft 160. As shown in FIG. 14,after the wheel sections 110 are mounted on the shaft 160, a spring clip174 may be mounted over and pressed onto the shaft 160 so that thespring clip 174 snaps into and remains in the annular recess 172. Thespring clip 174 increases the diameter of the shaft 160 at the first end162 to a diameter that is greater than the diameters of the centralbores 114 of the hub sections 112. Accordingly, the wheel sections 110are stopped by the spring clip 174 when reaching the first end 162 ofthe shaft 160. The axle 106 may also include a washer 176 or the likemounted between the spring clip 174 and the last mounted wheel section110. To provide easier installation of the spring clip 174 into theannular recess 174, the first end 162 of the shaft may be tapered asshown in FIGS. 13 and 14 so that pressing the spring clip 174 onto thefirst end 162 gradually expands the spring clip 172 when being mountedon to the shaft 160. Thus, the spring clip 174 remains engaged in theannular recess 172 until it is expanded with or without a tool by anindividual for removal of the spring clip 174 from the shaft 160, whichthen allows removal of the wheel sections from the shaft 160. At thesecond end 164 of the shaft 160 an annular shoulder 178 may be providedso that the first mounted wheel section 110 is spaced from the firstbracket section 168.

FIG. 2 shows the wheel 100 in the collapsed position having the tire 104mounted thereon. The tire 104 may be constructed from an elasticmaterial such as rubber. Furthermore, the inner diameter of the tire 104may be smaller than an outer diameter of a circle defined by the wheel100 in the expanded position. Accordingly, the tire may be easilymounted over the wheel 100 in the collapsed position. However, the tire104 may elastically expand when the wheel 100 is expanded. The elasticexpansion of the tire 104 may create a restoring force in the tire 104by which the tire 104 is pressed onto the rims 118 (for example theprojections 120 are pressed in the grooves 136) to maintain the tire 104on the wheel 100 during the operation of the wheel 100.

To expand the wheel 100 from a collapsed position to the expandedposition, each of the wheel sections 110 may be rotated by hand. In oneexample shown in FIGS. 15 and 16, the wheel 100 includes a hubcap 200 bywhich the wheel sections 110 may be rotated relative to each other toexpand the wheel 100. The hubcap 200 may include two opposing handles202 and 204 that can be held by an individual for rotating the hubcap200. The hubcap 200 may include a pin (not shown) on an inner surfacethereof that may engage inside the slot 140 of the last mounted wheelsection 110. The hubcap 200 may be rotationally mounted on the shaft106. Accordingly, when the hubcap 200 is turned about the shaft 106 byan individual, the pin on the inner surface of the hubcap 200 moves inthe slot 140 of the first wheel section 110 until the pin engages thesecond end 152 of the slot 140. After the first wheel section 110 isturned at the expansion angle, the pin 144 of the first wheel section110 engages second end 152 in the slots 140 of the second wheel section110 as described above. Accordingly, further rotation of the hubcap 200causes the second wheel section 110 to rotate relative to the thirdwheel section 110 at the expansion angle. Continuing the rotation of thehubcap 200 rotates the remaining wheel sections 110 until the wheel 100is completely expanded. The hubcap of 200 may be mounted on the shaft160 between the last mounted wheel section 110 and the spring clip of174. When holding the handles 202 and 204, an individual can also holdthe second bracket section 166 to provide leverage when expanding thewheel 100.

FIGS. 17 and 18 show a wheel 400 according to another example. The wheel400 is similar in certain aspects to the wheel 100. Accordingly, similarparts of the wheel 100 and the wheel 400 are referred to with the samereference numbers. The wheel 400 includes a plurality of wheel sections110 that are mounted on an axle 406 (shown in FIG. 17). The axle 406includes a first end 462 (shown in FIG. 17) and a second end (notshown). The axle 406 receives the wheel sections 110 by being insertedinto the central bores 114 of the wheel sections 110. The second end ofthe axle 406 includes a base 470 that is larger in diameter than thediameter of the central bore 114 of the wheel sections 110. Accordingly,when the wheel sections 110 are mounted on the axle 406, the wheelsections 110 are bound at the second end of the axle by the base 470. Toprevent the wheel sections 110 from being removed from the axle 406during the operation of the wheel 400, the second end of the axle 406may be threaded to receive a correspondingly threaded nut 480. Thus,tightening the nut 480 on threaded first end 462 of the axle 406prevents the wheel sections 110 from being removed from the axle 406during the operation of the wheel 400. Alternatively, the wheel 400 mayinclude a wheel holding mechanism similar to the wheel holding mechanismof the wheel 100 as described in detail above. The wheel 400 includes ahubcap 200 which may be used to expand the wheel 400 from the collapseposition to the expanded position as described in detail above withrespect to the wheel 100.

Referring to FIG. 18, the first mounted wheel section 110 may includetwo opposing handles 502 and 504 on the central hub section 112 that arepositioned similarly to the handles 202 and 204 of the hubcap 200.Accordingly, an individual can expand the wheel 400 from the collapsedposition by holding the handles 202 and 204 with one hand and rotatingthe handles 202 and 204 in one direction and holding the handles 502 and504 with the other hand and rotating the handles 502 and 504 in theopposite direction to rotate the wheel sections relative to each otherto expand the wheel 400 to the expanded position. The handles 502 and504 may be part of a hubcap (not shown) that is mounted on the axle 406before the first mounted wheel section 110 is mounted on the axle 406.Alternatively as shown in FIGS. 17 and 18, the handles 502 and 504 maybe an integral part of the first mounted wheel section 110.

Referring to FIGS. 19 and 20, a wheel 600 according to anotherembodiment is shown. The wheel 600 is similar in some aspects to thewheels 100 and 400. Accordingly, similar parts of the wheels 100, 400and 600 are referred to with the same reference numbers. The wheel 600includes a plurality of wheel sections 610. Each wheel section 610includes a hub section 612 with a central bore (not shown). Each wheelsection 610 includes a pair of spaced apart generally straight spokes616 on each side of the perimeter section of the hub section 612 thatproject radially outward and connect to a generally curved rim 618. Thedistance between each pair of spokes 616 may increase from the hubsection 612 to the rim 618. Accordingly, each pair of spokes 616 and thecorresponding rim 618 defines a generally trapezoidal shape. The wheel600 includes an axle 606 that is mounted through the central bores ofthe wheel sections 610. The axle 606 and the mechanisms and methods bywhich the axle 606 is operatively connected to the wheel and the cartare similar to the axle 106 and 406. Accordingly, a detailed descriptionof the axle 606 is not provided.

Referring to FIGS. 21-25 a wheel 800 according to another example isshown. The wheel 800 includes a hub assembly 802 and a tire (not shown)that is mounted on the hub assembly 802 as described below. The wheel800 also includes an axle 806 on which the hub assembly 802 and a tireare rotatably mounted. The hub assembly 802 includes a plurality ofwheel sections 810 that are concentrically mounted on the axle 806. Eachwheel section 810 includes a hub section 812 having a central bore 814for receiving a section of the axle 806.

The tire may be mounted on a plurality of rims 818 that are positionedalong a perimeter of a circle 817 that defines a central plane of thewheel 800. Each rim 818 is generally oriented perpendicular to thecircle 817 (shown in FIG. 24) and is convex relative to the hub sections812. Accordingly, each rim 818 is concave relative to the tire (notshown) so as to receive a curved section of the tire. Each rim 818 isattached to two spaced apart hub sections 812 by two spokes 816,respectively. The two hub sections 812 to which a rim 818 is attachedwith the spokes 816 are spaced apart so that the spokes 816 form aV-shaped support for each rim 818. For example, as shown in FIG. 22, thespokes 816 that support a rim 818 are connected to hub sections 812 arespaced apart by five hub sections 812. Thus, each hub section 812 hasone spoke 816 on one side thereof that partially supports a firstcorresponding rim 818, and another spoke 816 on the opposite sidethereof that partially supports a second corresponding rim 818.

FIGS. 23-25 show the expanded position of the wheel 800. The spokes 816are positioned on the hub sections 812 such that when the wheel 800 isin the expanded position, the spokes 816 are evenly distributed aroundthe wheel, i.e., radially spaced apart on the circle 817 at a similarexpansion angle. In the example of FIGS. 23-25, the spokes 816 are shownto be generally 30° apart in the expanded position of the wheel 800.FIGS. 21 and 22 show the collapsed position of the wheel 800. Tocollapse the wheel 800, the hub sections 812 may be rotated relative toeach other until the rims 818 contact each other and prevent furtherrotation of the hub sections 812. To expand the wheel 800, the hubsections 812 may be rotated in an opposite direction relative to eachother such that the wheel 800 reaches the expanded position shown inFIG. 23. Because each spoke 816 is located on a different hub section812, the wheel 800 may require a rotation of less than 180° forexpansion from the collapsed position to the expanded position.Accordingly, to expand the wheel 800 from the collapsed position asshown in FIG. 21, the spoke 820 is rotated clockwise until the spoke 820is positioned close to spoke 822 and is prevented from further rotationby an expansion limiting mechanism as described below. Simultaneously,the spoke 824 is rotated clockwise until it is positioned close to spoke826 and is prevented from further rotation by the expansion limitingmechanism. Thus, the largest rotation of a hub section 812 may be lessthan 180° to expand the wheel from the collapsed position to theexpanded position.

To prevent further rotation of the hub sections 812 relative to eachother when the wheel 800 reaches the expanded position shown in FIG. 23,the wheel 800 may include an expansion limiting mechanism as describedabove. Accordingly, each wheel section 810 may include a radial slot(not shown) on the hub section 812 and a pin (not shown) that may belocated on the hub section 812 opposite to the slot relative to thecentral bore 814. The arc length of each radial slot 140 may begenerally no greater than the expansion angle. In the example of FIG. 24the arc length of the radial slot is about 30°, which is the same as theexpansion angle.

A tire (not shown) may be mounted on the wheel 800 before or after thewheel is expanded. The tire may be constructed from a solid piece ofrubber or other type of plastic material that has sufficient elasticityto allow mounting of the tire on the wheel 800. Alternatively, the tiremay be in the form of an inflatable tube that may be mounted on the rims818. Accordingly, the tire may be inflated by an individual beforeoperating the wheel 810. Alternatively yet, the tire may be attached toone or more of the rims 818 such that the tire is maintained in amounted configuration on the wheel 800 in both the collapsed andexpanded positions of the wheel 800.

FIGS. 26-33 show several exemplary wheels and/or wheel sectionsaccording to the disclosure. A wheel section 1010 as shown in FIG. 26may include at least one spoke 1016 on each side of a hub section 1012.The wheel section 1010 also includes a least one rim 1018 attached toeach spoke 1016. Each spoke 1016 and the corresponding rim 1018generally define a T-shaped spoke and rim assembly. A wheel section 1110as shown in FIG. 27 may include at least one spoke 1116 on each side ofa hub section 1112. The wheel section 1110 also includes at least onerim 1118 attached to each spoke 1116. Each spoke 1116 and thecorresponding rim 1118 generally define an L-shaped spoke and rimassembly. According to the exemplary wheel sections 1010 and 1110, atleast one rim and at least one spoke may be attached to each other inany configuration. For example, an end of a spoke may be attached to acenter of the length of the rim as shown by the wheel section 1010 toprovide a generally T-shaped spoke and the rim assembly. With theexemplary wheel section 1110 however, the end of the spoke is attachedto one end of the rim. Therefore, a spoke and a rim may be attached toeach other in any configuration and with any type of offset relative toeach other.

FIGS. 28 and 29 show a wheel 1200 according to another example. Thewheel 1200 includes a plurality of wheel sections 1210, where each wheelsection 1210 may have a different configuration as compared to one ormore of the other wheel sections 1210. For example, each wheel section1210 may have different shaped spokes 1216. The spokes 1216 may bestraight, curved, L shaped, Z shaped and/or have any other shape thatmay be different from the spokes 1216 of one or more of the other wheelsections 1210. Depending on the shape of each spoke 1216, each spoke mayhave different thickness, may be constructed from a different materialand/or have a certain property that may be different from or similar toone or more other spokes 1216 of one or more other wheel sections 1210.A tire 1204 may be mounted on the wheel 1200 in both the collapsedposition and in the expanded position of the wheel 1200.

FIGS. 30 and 31 show a wheel 1300 according to another example. Thewheel 1300 includes a plurality of spokes 1316. Each spoke may beflexible so as to deform from an extended position corresponding to theexpanded position of the wheel 1300 to a deformed position correspondingto the collapsed position of the wheel 1300. FIG. 30 shows an example ofthe wheel 1300 in the process of being expanded between the collapsedposition and the expanded position shown in FIG. 31. In the extendedposition of the spokes 1316 as shown in FIG. 31, the spokes 1316 havesufficient collective rigidity to support the loads on the tire 1304 andthe hub assembly 1302 to provide operation of the wheel 1300 asdisclosed. However, the spokes 1316 are flexible so that the wheel 1300may be collapsed by deforming the spokes 1316 to collapse the wheel1300. As shown in the example of FIG. 30, the spokes 1316 may bedeformed by being bent and stacked on top of each other around the hub1312. The spokes 1316 may also provide a shock absorbing function forthe wheel 1300. The wheel 1300 may include a singular hub 1312 to whichall of the flexible spokes 1316 are attached. Alternatively, the wheel1300 may include a plurality of hub sections, where each hub section isrotatable relative to an adjacent hub section to facilitate collapsingand expanding of the wheel 1300 to which one or more spokes 1316 may beattached. As shown in FIGS. 30 and 31, the wheel 1300 may also include atire 1304, which may be similar to the exemplary tires disclosed herein.

FIGS. 32 and 33 show a wheel 1400 according to another example. Thewheel 1400 includes a hub 1412 to which the rim 1418 is attached. Therim 1418 includes a first rim section 1420 and a second rim section 1422that are pivotally mounted to the hub 1412 by one or more hinges 1424.As shown in FIG. 33, the first rim section 1420 and the second rimsection 1422 can be pivoted at the hinge 1424 to collapse the wheel 1400from the expanded position shown in FIG. 32 to a collapsed position (notshown). Thus, the size of the wheel 1400 may be reduced for storageand/or transportation upon collapsing the wheel from the expandedposition.

Referring to FIG. 34, a section of a wheel 1500 according to anotherexample is shown. The wheel 1500 includes at least one spoke 1516 and atleast one rim 1518 that is attached to the spoke 1516. The wheel 1500may not include a one-piece tire similar to the examples describedabove. Instead, a tire section 1504 is attached to each rim 1518.Accordingly, when the wheel 1500 is expanded to an expanded position,the tire sections 1504 collectively define a tire for the wheel 1500.Therefore, the tire for the wheel 1500 is defined by a plurality of tiresections 1504 and any gaps that may be present between adjacent tiresections 1504. As with the examples described above, the tire section1504 may be constructed from an elastic material such as rubber. Thetire sections 1504 may then be attached to a rim 1518 with an adhesive,one or more fasteners and/or one or more other types of attachmentdevices or procedures.

Referring to FIGS. 35-41, a wheel 1600 according to another example isshown. The wheel 1600 includes a hub assembly 1602. The wheel 1600 mayinclude a tire (not shown) that may be mounted on the hub assembly 1602.Alternatively, the wheel 1600 may include a plurality of tire sectionsas described above with respect to the wheel 1500. Alternatively yet,the wheel 1600 may operate without a tire. The wheel 1600 also includesan axle 1606 on which the hub assembly 1602 is rotatably mounted. Thehub assembly 1602 includes a plurality of wheel sections 1610 that areconcentrically mounted on the axle 1606. Each wheel section 1610includes a hub section 1612 having a central bore 1614 for receiving asection of the axle 1606.

The wheel 1600 includes a plurality of rims 1618 that are configured todefine a path on a circumferential or circular band 1617 having a width1619. The path defined by the rims 1618 may be substantially continuous.The circular band 1617 defines a circular contact area similar to a tire(shown in FIG. 38) between the wheel 1600 and the ground. In theexpanded position of the wheel 1600, each rim 1618 may be oriented suchthat at least one point on at least one rim 1618 contacts the ground. Inone example, each rim 1618 is positioned diagonally on the circular band1617. Each rim 1618 may be radially spaced apart from an adjacent rim1618 as long as the space does not provide a large enough gap tosubstantially disturb or hinder generally smooth rolling of the wheel1600 on the ground. Alternatively, each rim 1618 may not have a radialgap relative to an adjacent rim 1618. Alternatively yet, each rim 1618may have a radial overlap with an adjacent rim 1618. In the example ofFIG. 38, each rim 1618 has a small gap relative to an adjacent rim 1618.Each rim 1618 may also be curved so that points on adjacent rims 1618that are spaced apart at a certain angle are located on the circularband 1617. Thus, as shown in FIG. 35, the rim 1618 defines a portion ofa path on a generally continuous circle in the expanded position of thewheel 1600. In other words, the curvature of each rim 1618 may generallyfollow the curvature for the circle defining a plane of the wheel 1600.

Each rim 1618 is attached to two spaced apart hub sections 1612 by twospokes 1616, respectively. The two hub sections 1612 to which a rim 1618is attached with the spokes 1616 are spaced apart so that the spokes1616 form a V-shaped support for each rim 1618. For example, as shown inFIG. 41, the spokes 1616 that support a rim 1618 are spaced apart byfour hub sections 1612. Thus, each hub section 1612 has one spoke 1616on one side thereof that partially supports a first corresponding rim1618, and another spoke 1616 on the opposite side thereof that partiallysupports a second corresponding rim 1618.

FIGS. 35, 36 and 38 show the expanded position of the wheel 1600. Thespokes 1616 are positioned on the hub sections 1612 such that when thewheel 1600 is in the expanded position, the spokes 1616 are evenlydistributed around the wheel, i.e., radially equally spaced apart at asimilar expansion angle. In the example of FIG. 35, the spokes 1616 areshown to be generally 30° apart in the expanded position of the wheel1600. FIGS. 37, 39 and 40 show the collapsed position of the wheel 1600.To collapse the wheel 1600, the hub sections 1612 may be rotatedrelative to each other until the rims 1618 contact each other andprevent further rotation of the hub sections 1612. Each spoke 1616 mayhave a certain cross-sectional shape to provide a more compact collapsedposition for the wheel 1600. For example, each spoke 1616 may have adiamond shaped cross-section as shown in FIG. 41. Accordingly, when thewheel 1600 is collapsed, each spoke 1616 may be positioned relative toan adjacent spoke 1616 in the complementary or a formfitting manner.Therefore, the spokes 1616 may collectively occupy less space ascompared to a scenario where each spoke 1616 has a certain shape thatdoes not lend itself to such complementary fitting with an adjacentspoke 1616.

To expand the wheel 1600, the hub sections 1612 may be rotated in anopposite direction relative to each other such that the wheel 1600reaches the expanded position 1612. Because each spoke 1616 is locatedon a different hub section 1612, the wheel 1600 may require a rotationof less than 180° for expansion from the collapsed position to theexpanded position as described in detail with respect to the wheel 800,hence not repeated herein. Thus, the largest rotation of a hub section1612 may be less than 180° to expand the wheel 1600 from the collapsedposition to the expanded position.

To prevent further rotation of the hub sections 1612 relative to eachother when the wheel 1600 reaches the expanded position, the wheel 1600may include an expansion limiting mechanism as described above.Accordingly, each wheel section 1610 may include a radial slot (notshown) on the hub section 1612 and a pin (not shown) that may be locatedon the hub section 1612 opposite to the slot relative to the centralbore 1614. The arc length of each radial slot may be generally nogreater than the expansion angle.

Similar to the example of FIG. 34, each rim 1618 may include a tiresection (not shown) that is attached to each rim 1618. For example, eachtire section (not shown) may be a generally rectangular strip of rubberor like elastic materials that is attached to each rim 1618 along thelength of the rim 1618. Thus, each tire section generally follows theorientation and the spatial position of each rim 1618 on the circularband 1617 as described above. Accordingly, when the wheel 1600 isexpanded to an expanded position, the tire sections collectively definea tire for the wheel 1600. As with the examples described above, a tiresection may be constructed from an elastic material such as rubber. Thetire sections may then be attached to a rim 1618 with an adhesive, oneor more fasteners and/or one or more other types of attachment devicesor procedures.

A tire (not shown) may be mounted on the wheel 1600 before after thewheel is expanded. The tire may be constructed from a solid piece ofrubber or other type of plastic material that has sufficient elasticityto allow mounting of the tire on the wheel 1600. Alternatively, the tiremay be in the form of an inflatable tube that may be mounted on the rims1618. Alternatively yet, the tire may be attached to one or more of therims 1618 such that the tire is maintained in a mounted configuration onthe wheel 1600 in both the collapsed and expanded positions of the wheel1600.

FIGS. 45-56 illustrate another example of an embodiment of a wheel 1900.The wheel 1900 has similar structure and/or components of the wheel 100,and the other embodiments of the wheel described herein. Accordingly,similar terms are used to describe similar components. Referring toFIGS. 45-46, the wheel 1900 includes a hub assembly 1902 that isconnected to a tire or track assembly 1904. The track assembly 1904 is atracked portion or an infinite track that is defined by a plurality ofinterconnecting or interlocking track segments 1905. The track assembly1904 is connected to an axle 1906 of the hub assembly 1902 by aplurality of wheel sections 1910. The plurality of wheel sections 1910are aligned and mounted to the axle 1906. It should also be appreciatedthat the wheel 1900 can be formed of one or more of the wheel sections110, 610, 810, etc., or aspects or components thereof, as describedherein.

Similar to the other embodiments of a wheel disclosed herein, the wheelsections 1910 rotate about the axle 1906 to adjust the wheel 1900between an expanded position (or expanded configuration) (see FIG. 45)and a collapsed position (or collapsed configuration) (see FIG. 46). Asillustrated in FIG. 47, collapsing the wheel 1900 from the expandedposition to the collapsed position realizes a decrease in height H ofthe wheel 1900. The reduction in height H can be approximately 35% ofthe height of the wheel 1900 in the expanded position. However, in otherembodiments the reduction in height H can be any suitable or targetedrange of height reduction, including a 10% height reduction up to and/orexceeding a 50% height reduction. By reducing the wheel height in thecollapsed position, the footprint of the wheel 1900 is reduced, whichreduces the overall space or volume necessary to store the wheel 1900(e.g., stored in a vehicle trunk, garage, basement, luggage, or anyother suitable or desired location).

FIG. 48 illustrates an example of one of the wheel sections 1910. Thewheel section 1910 includes a hub section 1912 that defines a centralbore 1914 configured to receive a portion of the axle 1906. The wheelsection 1910 includes a plurality of spokes 1916 that project from thehub section 1912 to a rim 1918. In the embodiment illustrated in FIG.48, a first pair of spokes 1916 a radially extend from the hub section1912 to define a first rim 1918 a, while a second pair of spokes 1916 bradially extend from the hub section 1912 to define a second rim 1918 b.The first spokes 1916 a are positioned opposite the second spokes 1916b. In other embodiments, each wheel section 1910 can have any suitableor desired number of spokes 1916 and/or rims 1918. The hub section 1912can also include one or more radial slots 1940, which correspond to andfunction in the same manner as radial slots 140 (i.e., to limit therotation distance of each wheel section 1910 about the axle 1906).

FIGS. 49-52 illustrate an example of an embodiment of the track segment1905 used with the wheel 1900. With reference to FIGS. 49-51, each tracksegment 1905 has a generally arcuate cross-sectional shape in order toform the wheel 1900 when the plurality of track segments 1905 areinterconnected. The track segment 1905 includes an inner surface 1930opposite an outer surface 1932. The inner surface 1930 is configured toengage the wheel sections 1910, while the outer surface 1932 isconfigured to engage the ground, terrain, or other surface traversed bythe wheel 1900. Accordingly, the outer surface 1932 has a generallyarcuate shape. In the illustrated embodiment, the features of the innersurface 1930 also has a generally arcuate shape. However, thecross-section shape of the inner surface 1930 can be any suitable shapeto receive and allow for rotation of the wheel sections 1910 inaccordance with the disclosure provided herein.

The inner surface 1930 includes a plurality of ribs 1934. The ribs 1934are generally parallel to one another, and radially project away fromthe inner surface 1930 to define a plurality of circumferential grooves1936. Each of the grooves 1936 is configured to receive the rim 1918 ofone or more corresponding wheel sections 1910. Accordingly, the numberof grooves 1936 (and thus the number of ribs 1934 that define thegrooves 1936) depends on the number of wheel sections 1910 used in thewheel 1900. Any suitable number of grooves 1936 can be defined by eachtrack segment 1905.

Each track segment 1905 includes a plurality of circumferentialprojections 1950 that define slots 1954. The projections 1950 and slots1954 extend circumferentially along the track segment 1905 to facilitatea connection with adjacent track segments 1905. With specific referenceto FIG. 49, the track segment 1905 includes a central member 1958 fromwhich the plurality of projections 1950 extend. The central member 1958includes a first side 1962 opposite a second side 1966. An odd number ofprojections 1950 extend away from the first side 1962, while an evennumber of projections 1950 extend away from the second side 1966. In theillustrated embodiment, three projections 1950 extend away from thefirst side 1962 in a circumferential direction, and two projections 1950extend away from the second side 1966 in a circumferential direction.Adjacent projections 1950 on each side 1962, 1966 are spaced to definethe slots 1954. Each slot 1954 is sized and configured to receive aprojection 1950 from an adjacent track segment 1905. Similarly, eachprojection 1950 is sized to be received by a slot 1954 of an adjacenttrack segment 1905. To facilitate the connection of adjacent tracksegments 1905, each projection 1950 can include an aperture 1970 thatextends through the projection 1950. The apertures 1970 are alignedalong each side 1962, 1966 of the central member 1958 and are configuredto receive a dowel, shaft, or other suitable member 1974 (see FIG. 53)to secure or interconnect adjacent track segments 1905.

It should be appreciated that when the track segments 1905 areinterconnected to define the track assembly 1904, each groove 1936 ofthe track segment 1905 cooperates with the associated circumferentiallyaligned groove 1936 of adjacent track segments 1905 to form acircumferential groove 1936 around the circumference of the wheel 1900.Similarly, each rib 1934 of the track segment 1905 cooperates with theassociated circumferentially aligned rib 1934 of adjacent track segments1905 to form a circumferential rib 1934 around the circumference of thewheel 1900. The circumferential ribs 1934 maintain each wheel section1910, and more specifically the rims 1918 of each wheel section 1910, inthe appropriate or associated circumferential groove 1936. In addition,the circumferential ribs 1934 retain the one or more of the wheelsections 1910, and more specifically the rims 1918 of those wheelsections 1910, within the appropriate or associated circumferentialgroove 1936. Accordingly, as the wheel sections 1910 rotate about theaxle 1906 and slide within (i.e., move relative to) the respectivecircumferential groove 1936, the circumferential ribs 1934 assist withkeeping the wheel section 1910 in the respective circumferential groove1936. In the illustrated embodiment, the rims 1918 have a generallysquare or rectangular cross-sectional shape, as viewed along across-section that is taken in an axial direction parallel to the axle1906. The grooves 1936 have a complimentary cross-sectional shape inorder to receive the rims 1918, while also allowing the rims 1918 toslide within the respective groove 1936 (as the wheel section 1910rotates about the axle 1906). In other embodiments, the rims 1918 andthe grooves 1936 may have any complimentary cross-sectional shape.Generally, the grooves 1936 have a shape and/or size that corresponds tothe shape and/or size of the rims 1918. The grooves 1936 can beapproximately 0.10 inches to approximately 0.30 inches wide, and morepreferably approximately 0.20 inches wide. Each rim 1918 and/or groove1936 can also be sized to provide adequate clearance between the rim1918 and the ribs 1934 that define a portion of the groove 1936 when therim 1918 is received by the groove 1936. For example, the rim 1918 orgroove 1936 can have a width to provide approximately 0.010 inches toapproximately 0.030 inches of clearance between the rim 1918 and ribs1934, and more preferably approximately 0.014 inches of clearancebetween the rim 1918 and ribs 1934.

While FIG. 49 illustrates three projections 1950 on the first side 1962,and two projections 1950 on the second side 1966 of the central member1958, in other embodiments any number of projections may be used.However, in these other embodiments, an odd number of projections areprovided on one side of the central member 1958, and an even number ofprojections are provided on the opposite, other side of the centralmember 1958. For example, one side of the central member 1958 can have1, 3, 5, 7, 9, 11, 13, 15, 17, 19, etc. projections 1950, while theother side of the central member 1958 can have 2, 4, 6, 8, 10, 12, 14,16, 18, 20, etc. projections 1950. Generally, one side of the centralmember 1958 will have N number of projections 1950, while the other,opposing side of the central member 1958 will have N−1 (or N+1)projections 1950. While the track segment 1905 is defined above in termsof projections 1950, the track segment 1905 can be similarly defined interms of slots 1954. The track segment 1905 can have an even number ofslots 1954 on the first side 1962 of the central member 1958, and an oddnumber of slots 1954 on the second side 1966 of the central member 1958.Generally, one side of the central member 1958 will have N number ofslots 1954, while the other, opposing side of the central member 1958will have N−1 (or N+1) slots 1954.

Referring back to FIG. 50, each track segment 1905 can have any numberof ribs 1934 and any number of grooves 1936. In the illustratedembodiment, each track segment 1905 includes nine ribs 1934 and eightgrooves 1936. In other embodiments, each track segment 1905 can includeany number of ribs 1934, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,13, 14, 15, 16, 17, 18, 19, 20, or more. Further, in other embodiments,each track segment 1905 can include any number of grooves 1936, such as1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20,or more. The number of grooves 1936 generally corresponds to the numberof wheel sections 1910 (since each groove 1936 receives at least onewheel section 1910). In addition, each track segment 1905 can have anysuitable distribution of ribs 1934 and grooves 1936 on the projections1950. For example, in the illustrated embodiment, a plurality ofprojections 1950 have two ribs 1934 that define at least one groove 1936and a portion of a second groove 1936, while one projection 1950 (thecenter projection 1950 that projects on the first side 1962 of thecentral member 1958) has one rib 1934 that defines a portion of twogrooves 1936. However, in other embodiments, the projections 1950 canhave any suitable or desired number of ribs and/or channels (or portionsthereof). Further, the projections 1950 can have different numbers ofribs 1934 and/or channels 1936 (e.g., one projection 1950 can have tworibs 1934, while another projection 1950 can have five ribs).Accordingly, any suitable or desired number of ribs 1934 and/or grooves1936 can be positioned on each projection 1950.

Each rib 1934 has a rib height 1978. In the illustrated embodiment, therib height 1978 is approximately constant as the rib 1934 extends fromthe central member 1958. However, as the rib 1934 reaches an end of theprojection 1950 opposite the central member 1958, the rib height 1978decreases or has a curved end portion 1982. The curved portions 1982assist with avoiding contact with ribs 1934 of adjacent track segments1905 when all track segments 1905 are interconnected to form the wheel1900.

Referring to FIGS. 53-54, the plurality of track segments 1905 areconnected together to form the track assembly 1904, only a portion ofwhich is shown. As previously disclosed, the track segments 1905 areconnected by securement members 1974 received by apertures 1970 in theprojections 1950. While any suitable securement member 1974 can be used,preferably the track segments 1905 can rotate about the securementmembers 1974 to facilitate collapsing of the wheel 1900.

FIGS. 53-54 illustrate a portion 1986 of the track assembly 1904 formedby three track segments 1905. Any suitable number of track segments 1905can be interconnected to form the track assembly 1904. For example, asillustrated in FIGS. 45-46, twenty-four (24) track segments 1905 definethe track assembly 1904 that forms the wheel 1900. Stated otherwise,each track segment 1905 extends along approximately fifteen degrees(15°) of the wheel 1900 (i.e., 360 degrees divided by twenty-four (24)track segments). In other embodiments, each track segment 1905 canextend along any suitable number of degrees of the wheel 1900. Statedotherwise, any number of track segments 1905 can be interconnected toform the wheel 1900.

In order to secure the track assembly 1904 to the hub assembly 1902 whenthe wheel 1900 is in the collapsed position, at least one wheel section1910 a is secured or fixed to a portion 1986 of the track assembly 1904.Stated another way, the wheel section 1910 a is not configured to slidewithin the associated groove 1936 of the track assembly 1904. FIGS.53-54 illustrate the portion 1986 of the track assembly 1904 that issecured to the wheel section 1910 a. The portion 1986 includes aplurality of apertures 1988 that are defined by an associated extensionor protrusion 1989 that projects from ribs 1934 (or an edge of the ribs1934) on either side of the groove 1936. The apertures 1988 arecoaxially aligned on the sides of the groove 1936. Apertures or rimapertures 1990 are defined by a portion 1991 of the rim 1918 of thewheel section 1910 a (shown in FIG. 55). When the rim 1918 of wheelsection 1910 a is positioned in the groove 1936 (such that the groove1936 receives the rim 1918), the rim apertures 1990 are positioned intoalignment with respective apertures 1988 on the ribs 1934. A securementmember 1992 (shown in FIGS. 58-59) is received by the aligned apertures1988, 1990 to secure the portion 1986 of the track assembly 1904 (andthus the track assembly 1904) to the wheel section 1910 a. Due to thesecurement, the wheel section 1910 a does not slide within the groove1936 of the track assembly 1904. Other embodiments of the wheel 1900 caninclude a plurality of wheel sections 1910 a that are secured to, and donot slide within grooves 1936 of the track assembly 1904. In addition,any of the grooves 1936 can be configured to secure the track assembly1904 to the hub assembly 1902. Accordingly, any groove or grooves 1936can include the plurality of protrusions 1989 that project from opposingribs 1934 and define the aperture 1988.

As shown in FIG. 56, a plurality of spacers 1996 can be positioned alongthe axle 1906 between adjacent wheel sections 1910. The spacers 1996 canhave a central bore 1997 that receives a portion of the axle 1906, and aradial slot 1998 that is similarly shaped as and aligned with the radialslot 1940 (when assembled). The spacers 1996 are constructed from orcoated with polytetrafluoroethylene (PTFE), or a related polymer, toreduce friction between the wheel sections 1910 as the wheel sections1910 are rotated about the axle between the expanded and collapsedpositions. In addition, the spacers 1996 can assist with maintainingcorrect spacing of the wheel sections 1910 within the hub assembly 1902.

It should also be appreciated that FIGS. 45-46 illustrate that fourtrack segments 1905 engage or otherwise connect to each wheel section1910 when in the expanded position. In other embodiments, any number oftrack segments 1905 can be associated with each wheel section 1910(e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc.).

FIGS. 57-63 illustrate an alternative embodiment of a wheel 1900 a,which is substantially the same as the wheel 1900. Accordingly, similarparts of the wheel 1900 and the wheel 1900 a are referred to with thesame reference numbers. The wheel 1900 a includes a track assembly 1904that is defined by a plurality of interlocking track segments 1905 a. Inaddition, the axle 1906 also carries an end member or sprocket 1999.

FIGS. 62-63 illustrate an example of the track segment 1905 a used todefine the track assembly 1904 of the wheel 1900 a. The track segment1905 a has similarities to the track segment 1905, with similar partsbeing referred to with the same reference numbers. The track segment1905 a includes two projections 1950 on a first side 1962 of a centralmember 1958, and a single projection 1950 on a second side 1966 of thecentral member 1958. Accordingly, the two projections 1950 define oneslot 1954 on the first side 1962, while there are two slots 1954 on thesecond side 1966. With reference to FIG. 63, the track segment 1905 adefines the same number of ribs 1934 and grooves 1936 across a width ofthe track segment 1905 a as the track segment 1905. However, thedistribution of the ribs 1934 and grooves 1936 on each projection 1950of track segment 1905 a differs from track segment 1905. Morespecifically, the two projections 1950 on the first side 1962 of thecentral member 1958 each include two ribs 1934, and each define onegroove 1936 a portion of a second groove 1936. The single projection1950 on the second side 1966 of the central member 1958 includes fiveribs 1934, and defines four grooves 1936. To carry the additional ribs1934 and grooves 1936, the single projection 1950 on the second side1966 of the central member 1958 has a width that is greater than each ofthe two projections 1950 on the first side 1962 of the central member1958. In other embodiments of a track segment, each projection 1950 canhave the same width or a different width. Further, each projection 1950on a common side 1962, 1966 can have the same width or different widths.In addition, in other embodiments the number of ribs 1934 and grooves1936 (or portions thereof) can differ or vary on each projection 1950.It should be appreciated that any number of ribs 1934 and/or grooves1936 can be implemented or used in the wheel 1900, 1900 a.

In operation, the wheel 1900 can be adjusted between the expandedposition (shown in FIG. 45) and the collapsed position (shown in FIG.46). To adjust the wheel 1900 between positions, a user can rotate thehub assembly 1902, such as by applying a rotational force on the handles202, 204 of the hubcap 200. The rotation of the hubcap 200 rotates thewheel sections 1910 about the axle 1906, sliding the wheel sections 1910(and more specifically rims 1918) within the corresponding grooves 1936defined by the track segments 1905 of the track assembly 1904. It shouldbe appreciated that while wheel sections 1910 rotate about the axle1906, at least one wheel section 1910 a does not rotate as it is securedto a portion of the track assembly 1904. This assists with maintaining aconnection between the hub assembly 1902 and the track assembly 1904 (sothe track assembly 1904 does not fall off of the hub assembly 1902during adjustment between the expanded and collapsed positions).

As the wheel sections 1910 slide within the grooves 1936 of the trackassembly 1904 towards the collapsed position, the wheel sections 1910disengage and no longer support portions of the track assembly 1904.When the wheel sections 1910 are rotated about the axle 1906 intoalignment (see FIG. 46), the portions of the track assembly 1904 thatare no longer supported by the wheel sections 1910 collapse,transforming the wheel 1900 into the collapsed position.

As the wheel sections 1910 slide within the grooves 1936 of the trackassembly 1904 towards the expanded position, the wheel sections 1910engage and support portions of the track assembly 1904. Slots 1940 and1998 provide the same function as slots 140, assisting to guide thedistance or amount of rotation of the wheel sections 1910 about the axle1906. When the wheel sections 1910 are completely rotated apart aboutthe axle 1906 (see FIG. 45), the wheel 1900 is in the expanded position.This arrangement advantageously deploys the wheel sections 1910 withoutrequiring any additional user interaction. In addition, the spaced apartwheel sections 1910 maintain a circular shape of the wheel 1900 (i.e.,360 degrees) to maintain consistent contact with the ground (or terrainor other surface engaged by the track assembly 1904).

Referring to FIG. 42, a method 1700 for constructing a wheel accordingto one example is shown. The method comprises forming a plurality ofwheel sections (block 1702), and assembling the wheel sections on anaxle (block 1704). The method 1700 may also include forming a tire (notshown) and/or mounting or attaching a tire on the wheel sections (notshown), and/or mounting or attaching a track assembly (or plurality oftrack segments) to the wheel sections (not shown). A wheel according tothe disclosure may be constructed from any metal or metal alloys,plastic, composite materials, wood or a combination thereof. Forexample, each wheel section such as the wheel sections 110 of the wheel100 may be formed in one piece from a plastic material by injectionmolding. In an injection molding process, a mold having a cavitydefining a wheel section may be used. Molten plastic material isinjected in the mold and cooled. The molded and cooled wheel section isthen removed from the mold. The molded wheel section may also besmoothed or cleaned to remove injection molding residue. Alternatively,a wheel section may be constructed by stamping (i.e., punching using amachine press or a stamping press, blanking, embossing, bending,flanging, coining, or casting), forging, machining or a combinationthereof, or other processes used for manufacturing metal, composite,plastic or wood parts. Each wheel section may be formed in one piece.Alternatively, components of each wheel section may be formed byprocesses and materials described herein and assembled to form the wheelsection. For example, the wheel section 110 may be formed by assemblinga separately manufactured hub section 212, spokes 216 and rim 218. A hubsection 212, one or more spokes 216, and a rim 218 may be attached toeach other by one or more adhesives, welding, soldering and/orfasteners. The disclosed materials and/or processes may be used tomanufacture any of the disclosed wheel, axle and/or tire components. Atire may be manufactured from an elastic material to provide shockabsorption for a pull cart to which one or more disclosed wheels areattached. A tire may be formed from rubber or other plastic materials. Atire may be formed as an inflatable tube or a solid flexible material.

Referring to FIG. 43, a golf pull cart 1800 for supporting andtransporting a golf club bag is shown having wheels 100. Although thepull cart 1800 is shown with the wheels 100, any of the wheels describedherein may be used with a golf pull cart. The golf pull cart 1800 mayinclude a frame 1810 on which a golf club bag (not shown) may be rested.The golf club bag may also be supported by a bottom support 1812, abottom side support 1813 and a top side support 1814. The frame 1810 mayalso include one or more straps (not shown) for securing a golf club bagto the frame 1810. The pull cart 1800 may further include two feet 1820in 1822 that extend outwardly from the frame 1810 opposite to eachother. Each foot supports a wheel 100. The frame may also include ahinge 1824 having two hinge rods 1826 and 1828 by which the feet 1820 in1822 may be pivoted and collapsed so that the feet 1820 and 1822 extendalong the frame 1810. The frame 1810 may also collapse at the hinge soas to provide a compact golf pull cart 1800 for transportation to andfrom a golf course, driving range or any golf related facility. Acollapsed golf pull cart 1800 is shown in FIG. 44. To further reduce thesize of the golf pull cart 1800, the wheels 100 may be collapsed asdescribed in detail herein. Furthermore, the wheels 100 may be removedfrom the pull cart 1800 and stored separately. Thus, using the wheels100 or any of the wheels described herein can reduce the size of anyvehicle, such as a golf pull cart, for easier storage and/ortransportation. Alternatively, a golf club bag (not shown) may includeattachment points or axles for directly attaching two collapsible wheelsas described in detail herein to the golf club bag. For example, a golfclub bag may be provided with two collapsible wheels that can be storedin one or more pockets of the golf club bag. An individual may carry thegolf club bag or attach the two wheels to an axle on the golf club bag,expand the wheels, and pull the golf club bag by using the wheels. Theuse of collapsible wheels as described in detail herein is not limitedto golf pull carts. Collapsible wheels as described in detail herein maybe used for kayak carts, grocery carts, small wagons that are typicallyused by children, any type of luggage, luggage carts, coolers and/or anyother wheeled utility cart, trailer, enclosed storage device, or avehicle.

Although a particular order of actions is described above, these actionsmay be performed in other temporal sequences. For example, two or moreactions described above may be performed sequentially, concurrently, orsimultaneously. Alternatively, two or more actions may be performed inreversed order. Further, one or more actions described above may not beperformed at all. The apparatus, methods, and articles of manufacturedescribed herein are not limited in this regard.

While the invention has been described in connection with variousaspects, it will be understood that the invention is capable of furthermodifications. This application is intended to cover any variations,uses or adaptation of the invention following, in general, theprinciples of the invention, and including such departures from thepresent disclosure as come within the known and customary practicewithin the art to which the invention pertains.

What is claimed is:
 1. A wheel comprising: an axle; a tire; and aplurality of wheel sections, each wheel section comprising: a rimportion; a hub portion defining a rotational axis; a pair of spokes,each spoke connecting the hub portion to the rim portion of one of thewheel sections of the plurality of wheel sections; wherein the rimportion, the hub portion, and the pair of spokes of each wheel sectionare integrally connected; and wherein the plurality of wheel sectionsare rotatable relative to each other about the rotational axis from anexpanded position wherein the rim portions of the plurality of wheelsections cooperatively define a circle to a collapsed position whereinthe rim portions of the plurality of wheel sections each define asegment of the same circle.
 2. The wheel of claim 1, wherein the wheelsections are substantially fixed from rotation relative to each other inthe expanded position.
 3. The wheel of claim 1, further comprising atire configured to be mountable on the rim portions in the collapsedposition or the expanded position.
 4. The wheel of claim 1, wherein eachrim portion comprises a tire portion.
 5. The wheel of claim 1, eachwheel section comprising a radially configured slot and a pin configuredto be received in the slot of another wheel section, wherein movement ofthe pin of one wheel section inside the slot of an adjacent wheelsection defines a range of rotation of the one wheel section relative tothe adjacent wheel section.
 6. The wheel of claim 1, wherein theplurality of wheel sections define groups of wheel sections with eachgroup comprising a pair of the wheel sections, and wherein the spokes ofthe wheel sections of each pair of wheel sections extend from the hub ofthe corresponding wheel section to the same rim portion.
 7. The wheel ofclaim 1, wherein the rim portions substantially define a path on acircumferential band around the wheel sections in the expanded position.8. The wheel of claim 1, further comprising an axle configured toremovably receive the hub of each wheel section by being insertable in acentral bore of each wheel section being coaxial with the rotationalaxis of the wheel section, wherein each wheel section is rotationalrelative to the axle.
 9. The wheel of claim 1, wherein the tirecomprises a plurality of track segments.
 10. The wheel of claim 9,wherein the plurality of track segments define a plurality of groovesconfigured to receive the wheel sections, and further configured toallow the wheel sections to move relative to the grooves.
 11. The wheelof claim 9, wherein each of the track segments include a plurality ofprojections that extend from a central member, the projections partiallydefining a plurality of slots, a first side of the central memberincluding N number of projections, and an opposing second side of thecentral member including N−1 number of projections, wherein theprojections on the first side are configured to engage slots of a firstadjacent track segment, and the projections on the second side areconfigured to engage slots of a second adjacent track segment.
 12. Thewheel of claim 11, where N equals two.
 13. A method of manufacturing awheel comprising: forming a plurality of wheel sections so that eachwheel section comprises a rim portion, a hub portion defining arotational axis, and a pair of spokes, each spoke connecting the hubportion to the rim portion of one of the wheel sections of the pluralityof wheel sections; wherein the rim portion, the hub portion, and thepair of spokes of each wheel section are integrally formed; and whereinthe plurality of wheel sections are rotatable relative to each otherabout the rotational axis from an expanded position wherein the rimportions of the plurality of wheel sections cooperatively define acircle to a collapsed position wherein the rim portions of the pluralityof wheel sections each define a segment of the same circle.
 14. Themethod of claim 13, further comprising forming a locking mechanismconfigured to substantially fix the wheel sections from rotatingrelative to each other in the expanded position.
 15. The method of claim13, further comprising forming a tire configured to be mountable on therim portions in the collapsed position or the expanded position.
 16. Themethod of claim 13, further comprising forming a tire section on eachrim portion.
 17. The method of claim 13, further comprising forming aradially configured slot and a pin on each wheel section, the pinconfigured to be received in the slot of another wheel section, whereinmovement of the pin of one wheel section inside the slot of an adjacentwheel section defines a range of rotation of the one wheel sectionrelative to the adjacent wheel section.
 18. The method of claim 13,further comprising forming the plurality of wheel sections such that thespokes of two wheel sections extend from the hub of the correspondingwheel sections to the same rim portion.
 19. The method of claim 13,wherein the rim portions substantially define a path on acircumferential band around the wheel sections in the expanded position.20. The method of claim 13, further comprising forming an axleconfigured to removably receive the hub of each wheel section by beinginsertable in a central bore of each wheel section being coaxial withthe rotational axis of the wheel section, wherein each wheel section isrotational relative to the axle.